Medical history books, almost uniformly extol the virtues of vaccination. Upon reading these books, one is left with the impression that during the 1800s and into the 1900s, there were rampant plagues that killed countless scores of people and that, because of vaccines, this is no longer the case. This is certainly what we believed growing up, and most people we talk to have a similar impression. It generally permeates society as an established fact. The problem with these statements is that they are not supported by the evidence.